Rectifier bridge abnormity positioning method based on thyristor conduction characteristics

Abstract

The invention discloses a rectifier bridge abnormity positioning method based on thyristor conduction characteristics, and relates to the technical field of rectifier bridge abnormity detection, and the main points of the technical scheme are that the rectifier bridge abnormity positioning method comprises a fault rectifier bridge judgment step and a rectifier bridge fault bridge arm judgment step, the absolute values of the reading numbers are compared; if the positive and negative current absolute values are the same or within an allowable loss range, judging that the rectifier bridge is in a normal state; if the preset threshold value is exceeded, judging that the rectifier bridge is abnormal; wherein the step of judging the faulty bridge arm of the rectifier bridge comprises the following steps of: monitoring the conduction condition of a thyristor on an abnormal bridge arm of the rectifier bridge; through comparison with the voltage waveform of the alternating current input end, the effect is that the abnormal bridge arm and the specific thyristor in the rectifier bridge can be accurately and quickly positioned by accurately monitoring the positive and negative electrode current of the rectifier bridge and the conduction condition of the bridge arm thyristor, and the accuracy and efficiency of fault detection are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of rectifier bridge abnormality detection, and more specifically, to a rectifier bridge abnormality positioning method based on thyristor conduction characteristics. Background Art

[0002] In modern power electronics, the rectifier bridge is a crucial component whose main function is to convert alternating current (AC) into direct current (DC). This conversion is essential for many electronic devices and systems because DC is more stable and easier to store and use. Rectifier bridges are widely used in various fields, including industrial control, energy management, transportation, communication systems, and aerospace.

[0003] However, during long-term operation, the rectifier bridge may experience performance degradation or failure due to aging, overload or other external factors of its internal components (such as thyristors). If these failures are not discovered and handled in time, they may cause interruption or damage to the entire power system, thereby affecting the normal operation of various equipment and services that rely on the power system.

[0004] In order to ensure the stable operation of the rectifier bridge, traditional maintenance methods usually include regular inspection and repair. However, this method is not only inefficient, but may not be able to detect and deal with potential faults in a timely manner. Therefore, it is particularly important to develop a technology that can monitor the status of the rectifier bridge in real time and accurately diagnose faults.

[0005] Therefore, in order to solve the above technical problems, the present invention proposes a rectifier bridge abnormality positioning method based on thyristor conduction characteristics. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide a method for locating abnormalities in a rectifier bridge based on the conduction characteristics of a thyristor.

[0007] To achieve the above object, the present invention provides the following technical solutions: In the first aspect, the present invention proposes a method for locating abnormality of a rectifier bridge based on the conduction characteristics of a thyristor, including a faulty rectifier bridge judgment step and a rectifier bridge fault arm judgment step:

[0008] The faulty rectifier bridge judgment steps include:

[0009] Detect the positive and negative currents of the rectifier bridge, and take the absolute values ​​of the readings for comparison; if the absolute values ​​of the positive and negative currents are the same or within the allowable loss range, the rectifier bridge is determined to be in a normal state; if they exceed the set threshold, the rectifier bridge is determined to be abnormal, and the rectifier bridge is marked as an abnormal rectifier bridge;

[0010] Among them, the steps of judging the faulty bridge arm of the rectifier bridge include:

[0011] Monitor the conduction status of the thyristors on the abnormal rectifier bridge arms; determine the bridge arm voltage waveform that coincides with the input voltage waveform by comparing it with the voltage waveform at the AC input end, thereby determining the order in which the bridge arms are turned on; compare the positive and negative output currents of each bridge arm during the conduction cycle, and find a bridge arm with a significantly abnormal current difference, determine that the bridge arm is an abnormal bridge arm, and mark it.

[0012] Furthermore, the method for determining the threshold value includes:

[0013] Collect historical positive and negative current data of the rectifier bridge under normal operating conditions;

[0014] Calculate the deviation between each set of positive and negative current data;

[0015] The deviation distribution of these data is calculated, and the 95%-99% confidence interval of the deviation value is taken as the allowable deviation threshold.

[0016] Furthermore, in the step of judging the faulty rectifier bridge arm, if the rectifier bridge is single-phase, the single-phase AC voltage is collected; if the rectifier bridge is multi-phase, the line voltage between the phases is collected.

[0017] Furthermore, past fault data is collected and analyzed, and a fault tree model is constructed in combination with expert knowledge; various operating parameters of the rectifier bridge are collected through sensors; and the most likely fault type and damaged thyristor are inferred by combining the fault tree model and actual operating data.

[0018] Furthermore, the fault tree model represents the logical relationship between various operating data and different anomalies.

[0019] In a second aspect, the present invention proposes a rectifier bridge fault diagnosis system, which is applied to the rectifier bridge abnormality positioning method based on thyristor conduction characteristics, and the system includes:

[0020] Current detection module, used to detect the positive and negative currents of the rectifier bridge;

[0021] Bridge arm positioning module, used to locate abnormal bridge arms;

[0022] Fault diagnosis module, which uses the fault tree model to diagnose specific abnormal thyristors and fault causes;

[0023] The information acquisition module is used to collect various data in the rectifier bridge and send them to the fault diagnosis module, including the current, voltage, thyristor temperature and other data of the positive and negative poles of the rectifier bridge, so as to facilitate the subsequent construction of the fault tree model;

[0024] The report generation module is used to generate a fault diagnosis report, indicating the specific abnormal thyristor and its possible abnormal cause.

[0025] Furthermore, the current detection module, the bridge arm positioning module, the fault diagnosis module, the information collection module and the report generation module can be implemented by software, hardware, circuits or a combination of these.

[0026] In a third aspect, the present invention proposes a rectifier bridge abnormality positioning and fault diagnosis device based on the thyristor conduction characteristics, which implements the rectifier bridge abnormality positioning method based on the thyristor conduction characteristics.

[0027] Furthermore, the device is integrated into a rectifier bridge system or used as an external diagnostic tool.

[0028] In a fourth aspect, the present invention proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for locating abnormalities in a rectifier bridge based on the conduction characteristics of a thyristor.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention can improve the accuracy of fault detection and positioning:

[0031] By precisely monitoring the positive and negative currents of the rectifier bridge and the conduction status of the bridge arm thyristors, this technical solution can accurately and quickly locate the abnormal bridge arm and specific thyristors in the rectifier bridge; compared with traditional periodic inspections and manual troubleshooting methods, it greatly improves the accuracy and efficiency of fault detection.

[0032] 2. The present invention can realize real-time monitoring and preventive maintenance:

[0033] This technical solution can monitor the working status of the rectifier bridge in real time and discover potential faults in time, thereby realizing preventive maintenance; it helps to avoid production interruptions and equipment damage caused by sudden faults, and ensures the continuous and stable operation of the power system.

[0034] 3. The present invention can reduce maintenance costs and extend equipment life:

[0035] Through accurate fault diagnosis, technicians can carry out targeted repairs, avoiding unnecessary comprehensive inspections and replacement of parts, thereby reducing maintenance costs. At the same time, timely fault handling also helps to extend the service life of the rectifier bridge and related equipment.

[0036] 4. The present invention can improve system reliability and safety:

[0037] The reliability of the power system is crucial in key areas such as aerospace, defense, and data centers. This technical solution significantly improves the reliability and safety of the rectifier bridge and the entire power system through real-time monitoring and fault diagnosis, and reduces potential risks caused by power failures.

[0038] 5. The present invention can promote intelligent management and remote monitoring:

[0039] This technical solution can be integrated into an intelligent management system to achieve remote monitoring and automated management; it not only improves management efficiency, but also enables technicians to understand the working status of the rectifier bridge anytime and anywhere, providing strong support for rapid response and decision-making. DETAILED DESCRIPTION

[0040] The invention provides a rectifier bridge abnormality positioning method based on thyristor conduction characteristics, including a rectifier bridge abnormality positioning method based on thyristor conduction characteristics.

[0041] In recent years, with the rapid development of sensor technology, data processing and artificial intelligence, real-time monitoring and fault diagnosis of rectifier bridges have become possible. The technical solution proposed in the present invention is based on these advanced technologies. By monitoring the positive and negative currents of the rectifier bridge, the conduction conditions of the bridge arm thyristors and various operating parameters of the rectifier bridge, the real-time monitoring of the rectifier bridge state and accurate diagnosis of faults are achieved.

[0042] Since the rectifier bridge only plays a role in converting AC into DC, but does not change the value of the current and voltage itself;

[0043] Among them, when talking about "no change", the direction of the current is not considered, only the value, and the normal energy loss caused by the current flowing through the electronic components is not taken into account;

[0044] First, you need to find the abnormal rectifier bridge, the method is as follows:

[0045] The positive and negative currents of the rectifier bridge are detected, and the absolute values ​​of the readings are taken. The detection can be performed by a set current detection module, which can be a Hall sensor. It belongs to the prior art and will not be described here. Then, a comparison is made, which includes the following two possibilities:

[0046] 1) If the absolute values ​​of the currents at the positive and negative poles of the rectifier bridge are the same, or the difference between the two is within an allowable loss range (i.e. within the set threshold), the rectifier bridge is considered to be in a normal state;

[0047] 2) If the difference between the two exceeds the set threshold, the rectifier bridge is considered abnormal. The threshold is selected based on historical data;

[0048] The setting of the threshold is based on collecting the historical positive and negative current data of the rectifier bridge under normal operating conditions, calculating the deviation between each set of positive and negative current data, and then calculating the deviation distribution of these data, taking the 95%-99% confidence interval of the deviation value as the allowable deviation threshold, and data exceeding the threshold is abnormal.

[0049] It is worth noting that the data obtained by sampling needs to be smoothed, such as using a moving average method, to reduce the impact of measurement noise on the judgment results.

[0050] After determining the rectifier bridge with an abnormality, the second step is to determine the rectifier bridge arm with a fault.

[0051] There are many groups of symmetrical components on the rectifier bridge arm, namely a positive thyristor and a symmetrical negative thyristor. In each conduction cycle, there is always such a group of components that are turned on at the same time to form a power supply circuit.

[0052] The voltage waveform between each phase is collected at the AC input end of the rectifier bridge. The single-phase rectifier bridge collects the single-phase AC voltage, and the multi-phase rectifier bridge collects the line voltage between each phase.

[0053] Take a rectifier bridge working cycle, analyze the overlap of the rectifier bridge input voltage waveform and the output voltage waveform, and determine the turn-on sequence of the bridge arms of the rectifier bridge; then, detect the positive and negative output currents of each bridge arm during the conduction period and compare the current deviation values. If the current deviation value on a bridge arm is significantly different from that on other bridge arms, it is considered abnormal;

[0054] Taking the three-phase bridge rectifier circuit as an example, assume that the voltage phases of the three-phase AC power are A, B, and C in sequence, and take a set of voltage waveforms at the AC input end (the line voltage between each phase takes one cycle and belongs to the same conduction cycle). Within this cycle, the voltage waveform output by the rectifier bridge coincides with only one set of line voltage waveforms, and Uab→Uac→Ubc→Uba→Uca→Ucb reaches extreme values ​​in sequence, and only corresponds to a single set of thyristors being turned on, which means that the bridge arm where this set of thyristors is located is working. Based on this, if the voltage waveform of the current bridge arm shows a coincidence feature with a set of voltage waveforms taken from the AC input end, it means that the current bridge arm is in the on state during the period of waveform overlap, so the conduction order of the thyristor can be derived; then, according to the conduction order of the thyristor, the positive and negative output currents of each bridge arm are continuously compared during the conduction cycle. If the difference between the positive and negative current values ​​of the rectifier bridge during the conduction period of a certain group of thyristors is significantly different from the difference during the conduction period of other groups of thyristors, it proves that there is an abnormality in the currently turned-on bridge arm, that is, there is an abnormality in a group of thyristors on this bridge arm.

[0055] After the abnormal bridge arm is determined, the next step is to determine the specific abnormal thyristor and possible fault. To achieve this step, the use of a fault tree can be considered.

[0056] To this end, it is necessary to collect a large amount of past fault data, analyze it, and combine it with expert knowledge to build a fault tree model, which represents the logical relationship between various operating data and different abnormalities in the form of a tree. In this way, all possible causes of thyristor abnormalities are represented in the form of a fault tree. The application of this model is mature in the existing technology and will not be elaborated here.

[0057] The various parameters of the rectifier bridge are collected through sensors, including the current, voltage, thyristor temperature and other data of the positive and negative poles of the rectifier bridge;

[0058] This is the actual operation data, which is used as the basic data for analysis. Then, combined with the characteristics of each abnormal mode, the hierarchical structure of the fault tree is used to gradually infer the most likely fault type, including the thyristor that is most likely to be damaged (one positive thyristor / negative thyristor / both are damaged on this bridge arm);

[0059] Finally, the diagnosis results are summarized and a fault diagnosis report is generated, pointing out the specific abnormal thyristors and the possible causes of the abnormalities.

[0060] Ultimately, by accurately monitoring the positive and negative currents of the rectifier bridge and the conduction status of the bridge arm thyristors, this technical solution can accurately and quickly locate the abnormal bridge arm and specific thyristors in the rectifier bridge. Compared with the traditional regular inspection and manual troubleshooting methods, this greatly improves the accuracy and efficiency of fault detection;

[0061] This technical solution can monitor the working status of the rectifier bridge in real time and detect potential faults in time, thus achieving preventive maintenance. This helps to avoid production interruptions and equipment damage caused by sudden faults, and ensures the continuous and stable operation of the power system;

[0062] Through accurate fault diagnosis, technicians can carry out targeted repairs, avoiding unnecessary comprehensive inspections and replacement of parts, thereby reducing maintenance costs. At the same time, timely fault handling also helps to extend the service life of the rectifier bridge and related equipment;

[0063] In key areas such as aerospace, defense, and data centers, the reliability of the power system is crucial. This technical solution significantly improves the reliability and safety of the rectifier bridge and the entire power system through real-time monitoring and fault diagnosis, and reduces the potential risks caused by power failures;

[0064] This technical solution can be integrated into the intelligent management system to achieve remote monitoring and automated management. This not only improves management efficiency, but also enables technicians to understand the working status of the rectifier bridge anytime and anywhere, providing strong support for rapid response and decision-making.

[0065] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the specification and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A method for locating abnormality of a rectifier bridge based on the conduction characteristics of a thyristor, characterized in that: It includes the steps of judging the faulty rectifier bridge and the faulty bridge arm of the rectifier bridge: The faulty rectifier bridge judgment steps include: Detect the positive and negative currents of the rectifier bridge, and take the absolute values ​​of the readings for comparison; if the absolute values ​​of the positive and negative currents are the same or within the allowable loss range, the rectifier bridge is determined to be in a normal state; if they exceed the set threshold, the rectifier bridge is determined to be abnormal, and the rectifier bridge is marked as an abnormal rectifier bridge; Among them, the steps of judging the faulty bridge arm of the rectifier bridge include: Monitor the conduction status of the thyristors on the abnormal rectifier bridge arms; determine the bridge arm voltage waveform that coincides with the input voltage waveform by comparing it with the voltage waveform at the AC input end, thereby determining the order in which the bridge arms are turned on; compare the positive and negative output currents of each bridge arm during the conduction cycle, and find a bridge arm with a significantly abnormal current difference, determine that the bridge arm is an abnormal bridge arm, and mark it.

2. The method for locating rectifier bridge abnormality based on thyristor conduction characteristics according to claim 1 is characterized in that: The method for determining the threshold value includes: Collect historical positive and negative current data of the rectifier bridge under normal operating conditions; Calculate the deviation between each set of positive and negative current data; The deviation distribution of these data is calculated, and the 95%-99% confidence interval of the deviation value is taken as the allowable deviation threshold.

3. The method for locating rectifier bridge abnormality based on thyristor conduction characteristics according to claim 1, characterized in that: In the faulty rectifier bridge arm judgment step, if the rectifier bridge is single-phase, the single-phase AC voltage is collected; if the rectifier bridge is multi-phase, the line voltage between the phases is collected.

4. The method for locating rectifier bridge abnormality based on thyristor conduction characteristics according to any one of claims 1 to 3, characterized in that: The following methods are included to diagnose rectifier bridge faults using the fault tree model: Collect and analyze past fault data and build a fault tree model based on expert knowledge; Collect various operating parameters of the rectifier bridge through sensors; Combining the fault tree model with actual operating data, the most likely fault type and damaged thyristor are inferred.

5. The method for locating rectifier bridge abnormality based on thyristor conduction characteristics according to claim 4 is characterized in that: The fault tree model represents the logical relationship between various operating data and different anomalies.

6. A rectifier bridge fault diagnosis system, applied to the rectifier bridge abnormality positioning method based on thyristor conduction characteristics as described in any one of claims 3 to 5, characterized in that: The system includes: Current detection module, used to detect the positive and negative currents of the rectifier bridge; Bridge arm positioning module, used to locate abnormal bridge arms; Fault diagnosis module, which uses the fault tree model to diagnose specific abnormal thyristors and fault causes; Information collection module, used to collect various data in the rectifier bridge and send them to the fault diagnosis module; The report generation module is used to generate a fault diagnosis report, indicating the specific abnormal thyristor and its possible abnormal cause.

7. A rectifier bridge fault diagnosis system according to claim 6, characterized in that: The current detection module, bridge arm positioning module, fault diagnosis module, information collection module and report generation module are implemented through software, hardware, circuit or multiple combinations.

8. A rectifier bridge abnormality location and fault diagnosis device based on thyristor conduction characteristics, characterized in that: The device realizes the method according to any one of claims 1 to 5.

9. The device for abnormal location and fault diagnosis of a rectifier bridge based on the conduction characteristics of a thyristor according to claim 8, characterized in that: The device is integrated into a rectifier bridge system or used as an external diagnostic tool.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.